Amateur-built HP-14 SAILPLANE N990 accident near Nampa, Idaho

Probable cause

The pilot’s incorrect positioning of the wing flaps during the landing approach, which resulted in a loss of lift and hard landing.

NTSB analysis

The pilot reported that, after soaring for nearly 3 hours, he returned to the departure airport and made a traffic pattern approach for landing. On final approach, he lowered the wing flaps to 40 degrees. The pilot additionally reported that, because it appeared the glider was going to be too high, he further extended the wing flaps. Suddenly, the glider’s sink rate increased, and the glider touched down hard short of the runway. The glider bounced and yawed sideways, the landing gear collapsed, and the fuselage buckled as the glider slid to a stop. The pilot stated that he subsequently observed that the flaps were set to 90 degrees, which was 30 degrees beyond what he had intended.

Text from the NTSB. Open the NTSB docket for WPR12CA157 for the full record.